178 

 PTERYGOTUS TAURINUS.— Sa/<er. 



Blr. Salter afterwards proceeded to give an account of a most interesting 

 discovei-y made by the President and Hmself of a new Ptcrygotm in the quarry 

 at Ewyas Harold, near Pontrilas. Dr. M'Cullough has been at work for some 

 time in beds which were known to be low down in the Old Red Sandstone, and 

 which both he and Mr. Salter now believe to belong to the '"Ledbury Shales." 

 Here, in this district, occur crowds of the little seeds or spore-cases of Lycor 

 podiacere {Pachi/theca sphoirica of Hooker), fragments of leaves, roots, and appa- 

 rently of stems that may belong to the same plant. AH this of course led them 

 to expect remains of the great Crustacea which invariably occui- in this formation, 

 and the President's hammer, fortunate already in new species and genera of 

 fish, first struck upon the Ptcrygotus in this quarry. At first only a large head 

 was found, which was rather squarer than that of most species ; but afterwards 

 some fragments of the jaws, swimming foot, and chelate antennre successively 

 fell to the same hammer. Mr. Salter's acquaintance with the other species of 

 this remarkable tribe, enabled liim to recognise these fragments as belonging 

 to a new species. Judging from them, the creatui'e could scarcely have been lesa 

 than six feet in length. From its gieat size, and also in honour of one of the 

 most active members of the Woolhope Club, he had given it the name of 

 ^Haurinus" (applause). The Ptcrygotus taurinas has a squarish head-piece, 

 nearly a foot wide, squamate at the margin, and tubercular over the surface. In 

 this specimen the eyes are not preserved, thoiigh their place is seen. 



The antennoi are preserved, and are provided with sharp, cutting, lance- 

 like teeth. The tips are much more hooked at the end than is usual in other 

 species of the genus. The palpi, two of which are preserved, show abruptly 

 smaller terminal joints. The articulations of the great swimming foot are also 

 so broad as to be peculiar. From the iiosition of the foot under the carapace, 

 there is little do\ibt but that it belongs to the head with which it is associated. 

 A part of one of the hinder body-rings, and a fragment of a short roundish 

 ovate tail-piece, is also preserved. 



Ih neaily all points of structure this species [which rivals in size the 

 great Scotch "Seraphim," the Ptcrygotus AngHcus'] differs specifically from 

 it ; and it is to be remarked here, that of the fifteen or twenty species known 

 in Britain, none on the two sides of the border agree well with one another. 

 This is the case with the Silurian species, as with those of the Old Red. But 

 the maximum of size, and, apparently, of number of species, of this wonderful 

 group of Crustacea was at the base of the Old Red Sandstone, and notably in 

 the Ledbury shales, attaining some of them the length of seven feet, and varying 

 from this to a few inches. The genera Ptcrygotus, Himantopterus, Slimonia, 

 Stylonurus, Eurypterus, differ widely in details ; but all agree in having the head 

 distinct from the moveable 12 or 13 body segments, and in their being all 

 furnished -with liiobs. The only limbs belong to the head. The antennce, 

 furnished with claws, apparently provided the more active species with food. 



